1. Field of the Invention
The present invention relates to guide rails used in a semiconductor manufacturing apparatus for conveying band-form members such as a film carrier tape.
2. Prior Art
Typical band-form member conveying guide rails used in a semiconductor manufacturing apparatus have a structure as shown in FIGS. 3(a) and 3(b).
In this guide rail structure, a pair of guide rails 2A and 2B that guide both side portions of a band-form member 1 are installed so as to face each other. The guide rails 2A and 2B consist of rail main bodies 3A and 3B and vertical-direction guide plates 4A and 4B. The vertical-direction guide plates 4A and 4B are fastened to the upper surfaces of the rail main bodies 3A and 3B so as to form guide grooves 5A and 5B between the rail main bodies 3A and 3B and vertical-direction guide plates 4A and 4B, thus guiding the band-form members 1 in the vertical direction.
Guide rails 2A and 2B of this type are disclosed in, for instance, Japanese Patent Application Publication (Kokoku) No. H2-54664. In this prior art, a pair of guide rails are provided with upper plates with guide grooves in between.
In these conventional band-form member conveying guide rails, the band-form member 1 is conveyed while the entire upper and lower surfaces of both side portions of the band-form member 1 are regulated in the vertical direction by the guide grooves 5A and 5B that are formed by the rail main bodies 3A and 3B and vertical-direction guide plates 4A and 4B. Accordingly, the frictional resistance during the conveyance tends to be large. In particular, when the band-form member 1 is a film carrier tape, the thickness is as thin as 25 to 125 μm, and it is flexible. Thus, undulation and twisting, etc. would occur during the conveying process. As a result of such undulation and twisting, etc., the frictional resistance of the upper and lower surfaces of side portions of the tab tape against the guide grooves 5A and 5B increases, and problems such as shape deformation of the tab tape and damage to the tab tape, etc. occur. In cases where the band-form member 1 is a lead frame, undulation and twisting, etc. would not occur; however, when the frictional resistance is high, the motive power of the conveying power supply needs to be increased.
Furthermore, when some type of trouble occurs during the conveying of the band-form member 1, the conveyance must be stopped so as to remove the band-form member 1 from the guide grooves 5A and 5B. However, since the guide grooves 5A and 5B of the prior art are in a continuous form, it is difficult to remove the band-form member 1 out of these guide grooves 5A and 5B.